Numerical simulation of ballistic impact on cart brass

Soft and lightweight body armour is normally made by woven fabrics. The aim is to select a metal material that enhances its performance yet complies with NIJ standard level threat IIA. Autodyn software is used for the simulation tests of ballistic impact. The projectile is blunt-nosed cylindrical and rigid body. The material selected for target is thin Cart Brass plate with thirty material parameters of Equation of State, Johnson-Cook Strength and Strain Rate Correction. In order to validate the model, ten tests are conducted on Weldox 460E steel. It is successfully achieved with 95% of confident level. Then simulation begins with ten tests on Cart Brass target to measure thickness and ballistic limit velocity, with results of 5.5 mm and 373 m/s respectively. The impact and penetration process of post-damage mechanisms are highlighted and verified with literature review. Phenomenon obtained are Tensile and Spherical Compressive Axial Strain; Through Thickness Strain Wave; Transverse-Shear Deformation and Growth; Delamination; Local Shear Cone Formation and Membrane Tensile Failure. The final state matches the damage mechanism of body armour qualitatively so its behaviours are maintained. The real application is a layer of cart brass implanted into soft body armour to increase its performance.